The present invention generally relates to a medical image reconstruction system and method. More particularly, the present invention relates to a medical image reconstruction system and method for correcting the three-dimensional (3D) spatial position of a 3D image.
In general, 3D medical images, such as computed tomography (CT) images or ultrasonic images, provide an advantage in that it is possible to collectively and comprehensively examine a subject using 3D medical images. However, in order to more specifically observe the inner cross-sections of the subject, the use of 2D medical images may be more effective than the use of 3D medical images. When 3D medical images and 2D medical images are displayed together, a user can observe the subject both collectively and precisely.
As an example of a related-art approach of displaying 3D medical images and 2D medical images, Korean Patent Application Publication No. 10-2013-0138612 (published on Dec. 19, 2013) will be described as follows:
A related-art device for displaying 3D medical images and 2D medical images includes: a 3D image acquisition unit for acquiring a 3D medical image of a subject; a cross-section selection unit for selecting at least one cross-section of the subject on the basis of an external input to the acquired 3D medical image; a 2D image acquisition unit for acquiring a 2D medical image by scanning the subject to be corresponding to the selected at least one cross-section; and a display unit for displaying the 2D medical image and the 3D medical image.
Here, the cross-section selection unit includes: a window creator creating at least one window to be positioned above the acquired 3D medical image; a window controller moving the at least one window above the 3D medical image; and an additional cross-section selector additionally selecting at least one cross-section adjacent to the selected at least one cross-section.
In addition, the 2D image acquisition unit includes: a first image acquisition unit acquiring at least one first 2D medical image by scanning the subject to be corresponding to the selected at least one cross-section; a second image acquisition unit acquiring at least one second 2D medical image by scanning the subject to be corresponding to at least one cross-section adjacent to the selected at least one cross-section; and a synthesized image acquisition unit acquiring at least one synthesized 2D medical image by synthesizing the at least one first 2D medical image and the at least one second 2D medical image.
The related-art approach can acquire at least one synthesized 2D medical image by acquiring and synthesizing the 2D medical images corresponding to the selected at least one cross-section and the at least one cross-section adjacent to the selected cross-section. However, this approach cannot acquire a 2D medical image (i.e. a panoramic image or a cephalometric image in the case of a 2D dental image) by reconstructing image information in a specific area of paths along which X-rays are emitted (hereinafter, referred to as X-ray emission paths) from the sagittal or coronal cross-section.
Since 2D medical images corresponding to different cross-sections, which are spaced apart at least predetermined distances, are magnified at different degrees due to the fact that ultrasonic beams or X-ray beams tend to propagate radially, when a 2D medical image is acquired by overlapping medical images in a selection area (range) using a simple image synthesizing method used in the related art, the acquired 2D medical image becomes inaccurate.
When a CT operator is not experienced, the CT operator frequently takes CT images without accurately aligning with the position of a patient (subject). When CT images are taken with the position of the patient being misaligned, it is impossible to prevent horizontal asymmetry or distortion in the facial skeleton, unless CT geometry correction is performed. Thus, when a CT image acquired from a patient without inaccurately aligning the position of the patient is displayed through a medical diagnostic 3D viewer, the initial CT image appears distorted. In addition, when features are extracted from CT volume data or a panoramic image or a cephalometric image is automatically reconstructed without executing a CT geometry correction algorithm, the performance of a reconstruction algorithm is lowered, which is problematic.
In the related art of a dental computed tomography, a panoramic image is reconstructed manually. A user manually inputs the trajectory of the dental arch in a cross-sectional image -of the axial direction. And the panoramic image is generated by reconstructing a certain range of images vertical to the trajectory of the dental arch which is manually input. The reconstructed panoramic image is created by applying the manually input trajectory of the dental arch in a specific cross-section to the entirety of the cross-sections. However, since the positions of the trajectory of the dental arch on the cross-sections are different, when the panoramic image is reconstructed manually, no teeth appear on the panoramic image if the teeth are present outside of the trajectory of the dental arch.